(a) Field of the Invention
The present invention relates to a device and method for controlling exposure of electromagnetic waves from a base station.
(b) Description of the Related Art
At the present time, a downlink frequency of a mobile-communication base station is in the range of 800 MHz to 2 GHz, and one portable terminal uses a plurality of frequencies for communication with a base station because of the recent long term evolution (LTE) service.
An exposure degree of electromagnetic waves from the mobile-communication base station is lower than transmitted power of the portable terminal, but a user owning a portable terminal is exposed to the electromagnetic waves regardless of his intent so the exposure degree must not be neglected in comparison with an exposure amount of electromagnetic waves radiated from the portable terminal in the viewpoint of an accumulated amount of the electromagnetic waves. Further, in addition to the mobile-communication base station to which the portable terminal is connected, electromagnetic fields are simultaneously radiated from the base stations of networks of other service providers or the base stations of networks using voice communication and data transmission in a separate way. Therefore, the exposed user is being simultaneously exposed twenty-four hours to the radiated electromagnetic fields of many base stations.
A government-affiliated organization manually transports a portable antenna system (an antenna and a receiver) covering a radiation frequency of the actual base station to desired places and measures the electromagnetic waves in order to understand the real state of the exposure of electromagnetic waves from the base station. Such the method is very cumbersome and allows observation in a limited time and space. Further, the method may not catch an exposure situation in a building that is off-limits.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.